Comet Hartley 2 as seen by the Deep Impact spacecraft on Nov. 4, 2010 at 9:59 a.m. Eastern. The comet's nucleus is approximately 1.2 miles (2 kilometers) long.NASA/JPL-Caltech/UMD

This is an artist's rendition of the flyby spacecraft releasing the impactor, 24 hours before the impact event. Pictured from left to right are comet Tempel 1, the impactor, and the flyby spacecraft.NASA

Mission name: Deep Impact

Deep Impact

Mission to a Comet

Mission Overview
The Deep Impact mission was the first attempt to peer beneath the surface of a comet. The craft spanned 268 million miles (431 million kilometers) of deep space in 172 days. It then released an impactor roughly the size of a coffee table, which collided with the city-sized comet, Tempel 1, on July 4, 2005, at 1:52 a.m. EDT. This hyper-speed collision between spaceborne iceberg and copper-fortified, rocket-powered probe was the first of its kind.

Relevance to Astrobiology
Deep Impact provided the first analysis of materials from the interior of a comet and gathered data concerning the role of comets in the formation of planets and the origin of life. Studies on data from Deep Impact showed that the comet contained a substantial amount of organic material, and provided insight into the types of materials that comets could have delivered to the early Earth when life first originated. Deep Impact also showed that the interior was shielded from solar heating, meaning that this material from deep within the comet could be unchanged since the formation of the Solar System.

NASA Astrobiology Involvement
Numerous researchers supported by the NASA Astrobiology Program were involved in the analysis of data from Deep Impact. This includes data collected by the spacecraft itself as well as astronomers who observed the comet using telescopes or other space instruments. Astrobiologists were also involved in aspects of mission design and target selection for Deep Impact.

The Astrobiologists
Researchers supported by the NASA Astrobiology Institute element of the NASA Astrobiology Program used telescope observations to characterize the cometary target of the Deep Impact mission. Observations were also made to characterize the dust created following the impact with Tempel 1. These efforts were lead by Project Investigator Karen Meech at the University of Hawaii.

Major mission findings

July 04, 2005Material from a Comet

Data from Deep Impact shows that a cloud of fine powdery material was released when the impactor slammed into the nucleus of comet Tempel 1.

September 05, 2005The Comet's Structure

Deep Impact revealed a number of surprising facts about comet Tempel 1. The comet is made up of a fine dust that is weaker than a bank of powder snow, but that’s held together by gravity; what appear to be impact craters can be seen on the surface; a huge increase of carbon-containing materials were detected when analyzing the comet’s ejection plume, indicating that comets contain a substantial amount of organic material; and the comet’s interior is well shielded from solar heating, meaning that the ice and other material deep within the comet nucleus may be unchanged from the early days of the Solar System.

September 10, 2005Cometary Compounds

Astronomers, using data from NASA’s Sptizer Space Telescope and Deep Impact, made a list of compounds thought to be the recipe for planets, comets and other bodies in the Solar System. Included were silicates, or sand, clay, carbonates, iron-bearing compounds and even aromatic hydrocarbons.